One technique for fabricating composite parts involves infusing a dry fiber component with resin using a process referred to as resin infusion. In one variation of this process, referred to as vacuum assisted resin infusion, after the fiber component is vacuum bagged on a tool, a vacuum is drawn which both compacts the fiber component and draws resin through the component to produce a compacted, resin infused part.
The resin infusion process may present several problems in some applications. One of these problems involves the need to use a peel ply which may have a tendency to restrict the flow of resin from the resin source into the component being infused. Another problem relates to difficulties in tailoring the resin flow across the area of the component due to the fact that resin distribution media tend to distribute the resin uniformly across the area of the fiber component. This uniformity of resin flow may result in “trap-off” of certain areas of the component, sometimes referred to as “resin starvation”, caused by resin-infused areas isolating adjacent dry areas from active vacuum paths. Another problem involves the need for locating resin supply components, such as channels, tubing and runners off of the fiber component so that they do not leave any mark-off on the infused part. Locating these resin supply components off of the fiber component may limit resin supply, may increase infusion distances and may increase infusion time while restricting optimization of the resin supply for a particular component.
Still another problem with existing resin infusion processes results from the need for placing a flexible peel ply and a flexible resin distribution media in contact with the fiber component. This direct contact may result in a relatively rough surface finish on the part, commonly known as the bag side finish, which may be unacceptable in applications where a smooth surface finish is required, such as in aircraft applications requiring an aerodynamic surface finish.
Another problem arises in connection with infusion of integrated components comprising multiple parts. In the case of integrated components, prior infusion techniques that used simple tooling required a complex bagging and/or consumable arrangement, while those that used a simple bagging/consumable arrangement required complex tooling.
Accordingly, there is a need for a method and apparatus for resin infusion which may eliminate the need for a peel ply while allowing optimization of the resin supply across the area of the fiber component, hence controlling the quantity of resin supplied to particular regions on the component. There is also a need for resin infusion apparatus that increases tooling flexibility by locating resin supply hardware directly on top of the component being infused without causing part mark-off while providing a smooth cured part finish.